Dynamic Host Configuration Protocol (DHCP) is a network application protocol used by devices (DHCP clients) to obtain configuration information for operation in an Internet Protocol network. When a DHCP client (a computer or any other network-aware device) connects to a network, the DHCP client sends a broadcast query requesting necessary information from a DHCP server. The DHCP server manages a pool of IP addresses and information about client configuration parameters such as default gateway, domain name, the DNS servers, other servers such as time servers, and so forth. On receiving a valid request, the DHCP server assigns the DHCP client an IP address, a lease (length of time the allocation is valid), and other IP configuration parameters, such as a subnet mask and a default gateway. The broadcast query is typically initiated immediately after booting, and must complete before the DHCP client can initiate IP-based communication with other hosts.
A DHCP client (or host) using DHCP for IP address configuration typically renews an IP address (e.g., sends a new DHCP request, possibly providing an existing IP address to request the renewal of the lease to the IP address) only when timers associated with the IP address expire. However, if the host performs a handover from one (source) access network to another (target) access network, a lease to a particular IP address may not have necessarily expired and, therefore, the host would not send a new DHCP request over the target access network. Therefore, during handover the host would have no way to indicate the need to perform a handover of the network connections to the target access network.